And another guest post (yesterday’s post by this guest accidentally came up on 13 December – scroll back for more on resonance and damping if you missed it) :
Once again I was with my registrar with the expert knowledge of physics waiting for the cardiothoracic registrar to take down the mammary. It was as though time stood still. We were both looking at the clock, and reminiscing on the wonderful mechanics of (non digital) clocks. She commented to me in passing “I do miss the slow natural frequency of the pendulum of a grandfather clock” which made me consider the fast swinging pendulum of a cuckoo clock. Needless to say, my mind turned to the concept of natural resonance frequencies in invasive pressure monitoring systems, and I thought back to the days of my music lessons…
TRUE/FALSE The natural resonant frequency of a system is proportional to the stiffness or tension in the system, and inversely proportional to the mass.
TRUE/FALSE As in tightening a violin or guitar string, increasing the stiffness or tension will lead to an increase in the natural resonant frequency (a higher note on the instrument)
TRUE/FALSE Like the pendulum of a grandfather clock being slower than that of a cuckoo clock on the wall, the pulmonary artery tracing on the monitor is not as good as the arterial system, as the pulmonary artery system has a much longer system and as such more mass and a lower natural frequency
TRUE/FALSE The ideal system for an arterial monitoring system has a large length and very stiff tubing to ensure that its natural frequency is close to the frequency of the system being monitored
TRUE/FALSE The ideal frequency for a pressure monitoring system is determined by the pressure range being measured, rather than by the frequency of the system.